1. Field of Invention
The present invention relates to a hot-wire cutter and, more particularly, to a hot-wire cutter for cutting an annular work piece.
2. Related Prior Art
A hot-wire cutter is an important machine tool for cutting metal work pieces precisely. A conventional hot-wire cutter includes a brass wire (or “hot wire”) inserted through a work piece. The brass wire discharges to the work piece so that are electric arcs between the brass wire and the work piece. Thus, like a wire saw, the brass wire cuts the work piece. Under the control of an NC program, the conventional hot-wire cutter moves the work piece. Thus, the conventional hot-wire cutter cuts the work piece into a shape according to the NC program with small errors.
The conventional hot-wire cutter is controlled to move in XY/UV planes to find the centers of initial apertures, one after another, before the cutting under the control of the NC program is started. However, if the work piece is an annular element, and apertures are to be made in the work piece in radial directions, much labor and time are required to have the job done. Moreover, the center of processing cannot be retained, and initial apertures must be located in a line. Hence, there will be errors in the angles of the cutting in the final product of the work piece if the conventional hot-wire cutter moves the work piece in an XY plane to find the centers of the initial apertures of the annular work piece.
The present invention is therefore intended to obviate or at least alleviate the problems encountered in prior art.